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Biomedical subjects

L Solbiati

Publications and source records attributed to L Solbiati.

At least 37 records · Page 2Linked to original sources
PubMed1999

Small hepatocellular carcinoma: treatment with radio-frequency ablation versus ethanol injection.

PURPOSE: To compare the effectiveness of radio-frequency (RF) ablation with that of percutaneous ethanol injection in the treatment of small hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Eighty-six patients with 112 small (< or = 3-cm-diameter) HCCs underwent RF ablation (42 patients with 52 tumors) or percutaneous ethanol injection (44 patients with 60 tumors). Therapeutic efficacy was evaluated with dual-phase spiral computed tomography performed at least 4 months after treatment. RESULTS: Complete necrosis was achieved in 47 of 52 tumors with RF ablation (90%) and in 48 of 60 tumors with percutaneous ethanol injection (80%). These results were obtained with an average of 1.2 sessions per tumor with RF ablation and 4.8 sessions per tumor with percutaneous ethanol injection. One major complication (hemothorax that required drainage) and four minor complications (intraperitoneal bleeding, hemobilia, pleural effusion, cholecystitis) occurred in patients treated with RF ablation; no complications occurred in patients treated with percutaneous ethanol injection. CONCLUSION: RF ablation results in a higher rate of complete necrosis and requires fewer treatment sessions than percutaneous ethanol injection. However, the complication rate is higher with RF ablation than with percutaneous ethanol injection. RF ablation is the treatment of choice for most patients with HCC.

Aged↗
PubMed1999

Radio-frequency ablation of hepatic metastases: postprocedural assessment with a US microbubble contrast agent--early experience.

PURPOSE: To evaluate contrast agent-enhanced ultrasonography (US) in the detection of untreated tumor after radio-frequency (RF) ablation of hepatic metastases. MATERIALS AND METHODS: Twenty patients with solitary colorectal liver metastases underwent percutaneous RF tumor ablation. Pre- and postablation imaging was performed with nonenhanced and enhanced color and power Doppler US and contrast-enhanced helical computed tomography (CT). Initial follow-up CT and US were performed 24 hours after ablation. The findings at US and CT were compared. RESULTS: Nonenhanced US demonstrated intratumoral signal in 15 of 20 metastases before ablation. This signal increased after contrast agent administration. Contrast-enhanced US performed 24 hours after ablation demonstrated residual foci of enhancement in three tumors, whereas no US signals were seen in any tumor on nonenhanced scans. CT demonstrated small (< 3-mm) persistent foci of residual enhancement in these three tumors and in three additional lesions that were not seen at US (US sensitivity, 50%; specificity, 100%; diagnostic agreement with CT, 85%). All six patients with evidence of residual tumor underwent repeat RF ablation. CONCLUSION: Contrast-enhanced US may depict residual tumor after RF application and thereby enable additional directed therapy. The potential reduction in treatment sessions and/or ancillary imaging procedures might increase the ease and practicality of percutaneous ablation of focal hepatic metastases.

Aged↗
PubMed1999

MR imaging of pancreatic changes in patients with transfusion-dependent beta-thalassemia major.

OBJECTIVE: The aim of this study was to evaluate MR imaging changes of the pancreas in patients with transfusion-dependent beta-thalassemia major. SUBJECTS AND METHODS: Twenty patients with transfusion-dependent beta-thalassemia major were examined using MR imaging at 0.5 T, with spin-echo T1-weighted, fast spin-echo T2-weighted, and gradient-echo T2*-weighted sequences. Image analysis was performed to assess pancreas-to-fat signal intensity ratios for all pulse sequences. Pancreatic exocrine and endocrine function and serum ferritin levels were assessed. Twenty healthy volunteers underwent MR imaging with the same three sequences and served as a control group. RESULTS: The pancreas-to-fat signal intensity ratio was significantly decreased in 17 (85%) of the 20 patients on spin-echo T1-weighted images (p < .05), fast spin-echo T2-weighted images (p < .01), and gradient-echo T2*-weighted images (p < .01) when compared with the 20 volunteers in the control group. The pancreas-to-fat signal intensity ratio was significantly increased in three (15%) of the 20 patients on spin-echo T1-weighted images (p < .01) and fast spin-echo T2-weighted images (p < .05). In addition, in the 20 patients, we found a significant correlation between increased pancreas-to-fat signal intensity ratios and decreased serum trypsin levels (r = -.77, p < .01 for spin-echo T1-weighted sequences; r = -.75, p < .05 for fast spin-echo T2-weighted sequences; and r = -.74, p < .05 for gradient-echo T2*-weighted sequences). Likewise, for the 20 patients, we found a significant correlation between decreased pancreas-to-fat signal intensity ratios and increased serum ferritin levels for gradient-echo T2*-weighted images (r = -.65, p < .01). No correlation was found for the other clinical parameters evaluated. CONCLUSION: MR imaging revealed signal intensity changes in the pancreas of patients with transfusion-dependent beta-thalassemia major. Patients with a major impairment of the exocrine pancreatic function had higher signal intensity of the pancreas because of fatty replacement of the parenchyma.

Adolescent↗
PubMed1998

Power Doppler sonography: general principles, clinical applications, and future prospects.

Power Doppler sonography (PD) is a technique that displays the strength of the Doppler signal, rather than the flow velocity and directional information. Its increased flow sensitivity and better vascular delineation have been used to document the presence and characteristics of flow in vessels that are poorly imaged with conventional color Doppler (CD), to identify areas of ischemia, to demonstrate inflammatory hyperemia or increased and irregular flow in tumors, as well as to assess serial vascular changes related to interval therapy. The present review reports the general principles of PD, portrays the results of clinical studies available in the literature, and suggests future trends of development.

Blood Vessels↗
PubMed1998

New applications of ultrasonography: interventional ultrasound.

Since 1975-80, worldwide but mostly in Europe and Japan, sonography has become the imaging technique of choice for guiding percutaneous interventional procedures for diagnostic or therapeutic purposes. In the last 10 years, the most important advances in interventional ultrasound have occurred in therapeutic applications, fostering and facilitating the development of the so-called minimally-invasive techniques. Among all these new applications for the treatment of fluid collections, inflammatory diseases, benign and malignant tumors, the most recent dramatic advances have occurred in primary and secondary liver malignancies, which will be the focus of this review. The rationale for the local treatment of primary and secondary liver cancers differs according to the success of conventional treatments (e.g. surgery and chemotherapy) and to the survival rates of such conditions, depending on clinical stage, patient age, associated diseases, and so on. Ultrasound-guided percutaneous therapies for liver cancer can be divided into: (1) direct intratumoral injection of chemical agents, such as ethanol, hot saline and acetic acid; and (2) thermally-mediated techniques, such as radiofrequency ablation, interstitial laser photocoagulation, microwave therapy or cryotherapy. Through different mechanisms of action, all these methods induce cell death by coagulative necrosis. The clinical efficacy of some of these techniques has been clearly established, like percutaneous ethanol injection in the treatment of hepatocellular carcinoma. In contrast, experience with the other techniques is much more preliminary, mostly due to the limited availability of sufficient clinical trials and to the fascinating speed of technological development. We review the state-of-the-art of the two most promising techniques, namely radiofrequency ablation and interstitial laser photocoagulation, and the present preliminary clinical data in the treatment of hepatocellular carcinomas and liver metastases. Radiofrequency energy is delivered to the tumors by means of electrode-needles (14-17 G) electrically insulated along all but the distal portion of the shaft and percutaneously introduced into the targets under ultrasound guidance. In the short history of this method, several technologies have been tested and used, but 'multiple-hook' and 'internal-cooling' electrodes are currently the leading choices, providing large necrosis volumes (up to 5 cm in diameter for a single 12-min application with an array of three internal-cooling electrodes) in short sessions, under local or general anesthesia. Radiofrequency ablation has proved its usefulness in the treatment of hepatocellular carcinomas, achieving complete necrosis in over 85-90% of cases in lesions smaller than 5 cm in diameter and in single sessions, with a low rate (< 10%) of local recurrences. In the treatment of liver metastases, whose very poor responsiveness to percutaneous ethanol injection and other 'chemical' therapies is extensively reported in the literature, radiofrequency ablation has 65-75% reported complete efficacy in the control of local tumor growth in lesions not exceeding 4 cm. Such great efficacy has been so far coupled with very low rates of major side-effects (< 2%), most of them requiring no surgical repair. Interstitial laser photocoagulation induces thermally-mediated coagulation through thin optic (Nd:YAG) fibers percutaneously inserted into the target under ultrasound guidance. Multiple fibers (beam splitters) are usually required to achieve a sufficiently wide necrosis volume. The reported success rate (complete necrosis and local control of tumor growth) ranges 45-75%) of the lesions, mostly liver metastates from colorectal carcinoma. An equally low rate of complications is reported for interstitial laser photocoagulation as for radiofrequency ablation, that is no more than 2-3% of cases. (ABSTRACT TRUNCATED)

Carcinoma, Hepatocellular↗
PubMed1998

Large-volume tissue ablation with radio frequency by using a clustered, internally cooled electrode technique: laboratory and clinical experience in liver metastases.

PURPOSE: To evaluate whether coagulation necrosis achievable with radio-frequency (RF) ablation can be increased by using a cluster of closely spaced electrodes. MATERIALS AND METHODS: RF was applied to ex vivo liver (n = 68), in vivo liver (n = 12), and in vivo muscle (n = 15) by using a cluster array of three separate internally cooled electrodes spaced 0.5 cm apart. The diameter of coagulation necrosis achieved with optimal RF deposition (1,400-2,150 peak mA) for 5-60 minutes of RF application was determined for electrode tip lengths of 1.5-3.0 cm and compared with that obtained by using a single electrode and otherwise similar technique. Ten patients with solitary intrahepatic colorectal metastases were also treated by using cluster electrode RF ablation. RESULTS: In ex vivo liver, simultaneous RF application to electrode clusters for 15, 30, and 45 minutes produced 4.7 cm +/- 0.1, 6.2 cm +/- 0.1, and 7.0 cm +/- 0.2 of coagulation necrosis, respectively. In in vivo liver and muscle, RF applied to electrode clusters for 12 minutes yielded 3.1 cm +/- 0.2 and 7.6 cm +/- 0.4 of coagulation, respectively. RF application to a single electrode produced maximal coagulation of 2.9 cm in ex vivo liver, 1.8 cm in in vivo liver, and 4.3 cm in muscle (P < .01, all tissues). In colorectal metastases, a single 12-15-minute application of RF to an electrode cluster induced 4.5-7.0 cm of coagulation necrosis. CONCLUSION: Simultaneous RF application to a cluster of three closely spaced internally cooled electrodes enables a larger volume of coagulation in ex vivo liver, in vivo tissues, and hepatic colorectal metastases than previously reported.

Animals↗
PubMed1998

[Neuroleptanalgesia in patients undergoing percutaneous, ultrasound-directed radiofrequency for primary or secondary, single or multiple hepatic neoplasms].

BACKGROUND: The use of percutaneous ultrasound-directed radiofrequency is a recent technique in non-surgical therapy of some neoplastic liver lesions. Purpose of this study is to demonstrate that the use of a narcosis-free analgesia allows to perform this procedure, which is generally painful and badly by the patient. METHODS: We treated 51 patients for a total of 126 procedures; the first 17 patients underwent a mono- or multipolar technique with uncooled electrodes, while the remaining 34 patients have been treated with double perfusion lumen electrodes with the chance of tipcooling. We used diidrobenzoperydol and fentanyl with a mean dose for each session of 209 micrograms for the first 17 patients and 109 micrograms for the other 34. RESULTS: Using VAS, we obtained a painless procedure in 42 patients and mild-pain sensations in 9 patients, while one hour after the procedure painless or light-pain sensation were observed in 49 patients and mild-pain in 2 patients, which required the use of FANS i.v. At discharge, all patients were pain-free or with very light pain sensation. We reduced the intra-hospital observation of patients from 5 to 3 hours, once the technique has been modified. 4 patients complained about nausea and 1 of these emesis. We did not observe any cardiovascular, respiratory and/or neurological complications. CONCLUSIONS: The use of neuroleptanalgesia allowed us to perform the described procedure with a good feeling by the patients.

Aged↗
PubMed1998

[A project for the organization and planning of a diagnostic ultrasonography area at a radiology department].

PURPOSE: The increasing use of ultrasound (US) for both diagnostic and interventional procedures has not been supported yet by proper and adequate planning of dedicated rooms. Therefore we studied both the organization and the design of such areas. METHODS AND DISCUSSION: As for organization, we considered: a) the kind of examination performed; b) the main department activity (in-/outpatients, diagnostic or interventional procedures); c) the schedule for each room by examination type and timing (patient preparation, actual examination and read-out times). As for room design, we studied the size and location of the diagnostic unit, dressing rooms, entrances and restrooms, as well as the furniture in general. We also studied the location of waiting rooms and corridors, the location and size of the read-out areas, and the room for post-interventional monitoring, as well as all the details about microclimate and lighting. Then we designed two different modules with the relevant planimetry: one featuring two adjacent diagnostic rooms and the other featuring a single diagnostic room. Some ergonomic solutions are also proposed concerning the location of the US system relative to the stretchers entrance and the location of the post-interventional monitoring room relative to the radiologic room(s). Finally, we evaluated the size of some peculiar pieces of equipment of a radiologic room by their function. CONCLUSIONS: The functional arrangement of the diagnostic US unit and its space requirements, permits to optimize the use of the whole structure complying with the ergonomic criteria for operators and enabling the rapid throughout of patients with no waste of time.

Hospital Design and Construction↗
PubMed1997

Percutaneous US-guided radio-frequency tissue ablation of liver metastases: treatment and follow-up in 16 patients.

PURPOSE: To determine the potential efficacy of radio-frequency (RF) ablation of liver metastases during long-term follow-up. MATERIALS AND METHODS: Sixteen patients with 31 hepatic metastases were treated with percutaneous, ultrasound-guided RF ablation. RF was applied to monopolar electrodes (2-3-cm tip exposure) either individually or within a multiprobe array (two to four probes) for 6 minutes at 90 degrees C over one to four treatment sessions per metastasis. RESULTS: In only one of 75 sessions, a moderate complication, self-limited intraperitoneal hemorrhage, was observed. Four patients (four lesions) underwent surgical resection 15-60 days after RF treatment. Residual, viable tumor was seen in all of these patients. The remaining 12 patients were followed up for 9-29 months (mean, 18.1 months). In these patients, 18 of 27 lesions remained stable or decreased in size and showed no enhancement at computed tomography and/or magnetic resonance imaging for at least 9 months. Two patients died of disseminated disease at 13 months and one at 16 months. Disease-free survival was achieved in eight patients. CONCLUSIONS: RF ablation appears to be a simple, safe, and potentially effective treatment for selected patients with liver metastases and may become a less invasive alternative to surgical therapy.

Aged↗
PubMed1997

Saline-enhanced radio-frequency tissue ablation in the treatment of liver metastases.

PURPOSE: To assess the effect of intraparenchymal saline injection on the results of radio-frequency (RF) tissue ablation. MATERIALS AND METHODS: Ex vivo and in vivo animal RF ablation was performed with and without intraparenchymal saline injection. Initially, saline was injected as a bolus (1-20 mL) before RF application. For subsequent in vivo studies, saline was injected as a bolus before RF application or continuously (1 mL/min) during RF application. Finally, 14 patients with liver metastases and one patient with primary cholangiocarcinoma were treated with the continuous infusion technique. A single RF electrode (tip exposure, 1-3 cm) was used with various ablation parameters. RESULTS: With pretreatment bolus injection of saline, lesions measured 1.4 cm +/- 0.1, 1.6 cm +/- 0.2, and 1.2 cm +/- 0.1 in ex vivo liver, in vivo animal muscle, and in vivo animal liver, respectively. Without saline enhancement, lesion sizes were 1.0 +/- 0.2, 1.2 +/- 0.2, and 0.8 +/- 0.1 cm, respectively. With continuous saline injection in in vivo pig liver, lesion size was 1.8 - 4.1 cm in diameter. In human tumors, necrosis volume was variable, but complete necrosis was seen in 13 of 25 lesions (diameter, 1.2-3.9 cm). Partial necrosis greater than 50% was seen in 12 lesions (diameter, 1.5-4.5 cm). CONCLUSION: Saline-enhanced RF ablation might permit percutaneous destruction of large liver lesions.

Adult↗
PubMed1997

Hepatic metastases: percutaneous radio-frequency ablation with cooled-tip electrodes.

PURPOSE: To assess the feasibility and safety of using cooled-tip electrodes to increase the volume of coagulation necrosis obtained or reduce the number of treatment sessions necessary with percutaneous tumor radio-frequency (RF) ablation. MATERIALS AND METHODS: Twenty-nine patients with 44 hepatic metastases (1.3-5.1 cm diameter) from colorectal (n = 22), gastric (n = 5), pancreatic (n = 1), or breast (n = 1) carcinoma were treated with RF ablation using cooled-tip, 18-gauge electrodes with 2-3 cm tip exposure. Each tumor was treated in one or two treatment sessions. RESULTS: Technical success, ablation of all visualized tumor, was achieved in 40 (91%) metastases. Findings at computed tomography (CT) and magnetic resonance (MR) imaging performed 3-6 months after treatment confirmed complete necrosis of the entire metastasis in 66%. Disease-free survival was 50% at 12 months and 33% at 18 months, with localized progression of disease in 34% of treated lesions. Overall survival was 100%, 94%, and 89% at 6, 12, and 18 months, respectively. Only one complication, self-limited hemorrhage, was seen. CONCLUSION: Use of cooled-tip electrodes was a safe and feasible adjunct for tumor RF ablation therapy that produced larger volumes of coagulation necrosis with fewer electrode insertions than is produced with other RF ablation techniques.

Aged↗
PubMed1996

Radiofrequency tissue ablation: increased lesion diameter with a perfusion electrode.

RATIONALE AND OBJECTIVES: We sought to induce large zones of coagulation necrosis using radiofrequency (RF) with perfusion electrodes and to define optimal parameters for this system. METHODS: We developed RF electrodes with internal cannulas to enable tip perfusion. Lesions were created with monopolar RF in ex vivo and in vivo liver and muscle tissue with and without perfusion of the electrode tip using 0 degree C saline. In separate experiments, wattage, current, procedure duration, tip exposure, and perfused tip temperatures were studied. RESULTS: In ex vivo liver tissue, a maximum lesion diameter of 3.1 cm without charring occurred with perfusion at 12 min and 50 W. In in vivo liver tissue with perfusion (tip temperature = 25-35 degrees C) and a 3-cm tip exposure, 80 W were deposited in muscle tissue and 65 W in liver tissue for 12 min without inducing charring. Lesion diameters were 4.5 cm and 2.4 cm, respectively. By comparison, without perfusion a maximum of 20 W could be deposited into either tissue type, resulting in 1.8-cm muscle lesions and 1.2-cm liver lesions. Tip temperatures between 45 degrees C and 55 degrees C resulted in charring. Smaller but predictable lesion diameters were created with a lower power, a shorter tip exposure, or both. Of all the parameters, diameter correlated best with the current applied. CONCLUSION: Perfusion of RF electrodes with chilled saline allows for increased power deposition without tissue charring, increasing the volume of coagulation necrosis created with a single electrode insertion. Perfusion electrodes therefore might decrease the number of probe insertions required for percutaneous tumor ablation therapy or allow for the treatment of larger lesions.

Animals↗
PubMed1995

Adjuvant therapy with essential fatty acids (EFAs) for primary liver tumors: some hypotheses.

Hepatocarcinoma is responsible for approximately 1 million deaths annually. It is usually discovered at an advanced stage and, if inoperable, has a poor prognosis. New therapies combining chemotherapy, hyperthermia, radiotherapy and immunomodulators have been recently attempted with various levels of success. Once the tumor is detected at an early stage, some possibilities of cure seem to emerge either by intratumoral percutaneous injection (PEI) of alcohol or by chemoembolization and interstitial hyperthermia. When the tumor volume is more than 5 cm, these therapies are less successful and radiotherapy can be used. All the techniques described have some limits; PEI, for instance, does not achieve a complete eradication of lesions > 3 cm and a non-homogenous alcohol distribution within the tumor leads to areas of necrosis. Radiotherapy, even if effective, is limited by dose-related radiation hepatitis. Another important limiting factor is the incomplete response to therapy and tumor recurrence. Essential fatty acids, especially gamma linolenic acid (GLA) and eicosapentaenoic acid (EPA) are discussed here for their ability to control primary tumor proliferation and increase response to chemotherapy, radiotherapy and hyperthermic treatment, thanks to their effects on cellular membranes (increased lipoperoxidation and modification of tumor stroma).

Animals↗
PubMed1994

Chemical parathyroidectomy for recurrence of secondary hyperparathyroidism.

To avoid the risks of reoperation, we treated 15 uremic patients on regular extracorporeal dialysis and affected by hyperparathyroidism recurring after subtotal parathyroidectomy with ultrasound-guided ethanol injection. Follow-up was extended to 12 months after the last injection and for 11 patients to 24 months. Plasma parathyroid hormone concentration, as measured with a carboxyterminal parathyroid hormone (c-PTH) radioimmunoassay (normal, 0.2 to 2 ng/mL), significantly decreased from a basal value of 19.29 +/- 14.73 ng/mL to 11.19 +/- 9.54 ng/mL at 1 month, 7.45 +/- 4.99 ng/mL at 6 months, 6.91 +/- 4.71 ng/mL at 12 months, and 6.51 +/- 3.89 ng/mL at 24 months. Total and bone alkaline phosphatase decreased in parallel. The only remarkable side effect was transient dysphonia, which occurred in two cases. These data suggest that the technique of ultrasound-guided fine-needle ethanol injection might be a valuable alternative to surgery for recurrent hyperparathyroidism after subtotal parathyroidectomy in selected patients. This should be confirmed in larger series of patients and with a more prolonged follow-up.

Adult↗
PubMed1994

Color Doppler sonography of salivary glands.

OBJECTIVE: We used color Doppler sonography to evaluate the vascular anatomy of the salivary glands and to analyze physiologic changes that occur during salivary stimulation in normal subjects and the flow alterations that occur in diseased glands. SUBJECTS AND METHODS: The vascular appearance of the three major salivary glands was examined in healthy volunteers (n = 24); in patients with chronic autoimmune diseases, including Sjögren's syndrome (n = 23) and salivary sarcoidosis (n = 2); and in a variety of benign (n = 49) and malignant (n = 13) nodules. Physiologic changes were assessed in healthy volunteers by means of a stimulation test with lemon and were quantified with color images and spectral analysis. Tumor vascularity was graded on a four-step analog scale of 0 to (+3) and classified as either peripheral or hilar, depending on the distribution of vessels. RESULTS: In the control subjects, color Doppler imaging accurately reflected the complex vascular anatomy of the salivary glands and showed dramatic changes occurring in parenchymal vessels during lemon stimulation as a result of the intense hyperemia associated with the secretion of saliva. Sjögren's syndrome and sarcoidosis showed a diffuse hypervascular pattern when morphologic changes of salivary parenchyma were seen on gray-scale sonograms. Benign tumors showed a lower grade of vascularity than did malignant tumors. All but one of the hypovascular nodules graded as 0 (n = 8) and + (n = 23) were benign. Conversely, eight of 11 nodules labeled with the highest grade of tumor vascularity (+3) were malignant. When the pattern of tumor flow signals was peripheral, it could be considered specific enough to aid in diagnosing pleomorphic adenoma. Peak systolic velocities greater than 60 cm/sec were never detected in benign tumors and were seen in only 44% of malignant tumors. CONCLUSION: Color Doppler sonography is a promising technique for analyzing the vascularity of the salivary glands and for characterizing some pathologic conditions. Our experience suggests that color Doppler sonography can provide additional diagnostic information in patients with chronic inflammatory diseases or suspected malignant tumors and can help in differentiating pleomorphic adenomas from other salivary gland tumors.

Adult↗
PubMed1994

[Morphologic imaging of thyroid carcinoma].

Ultrasonography (US) is the choice morphological imaging modality in the study of thyroid carcinomas. The present technological evolution (high frequency probes, development of Colour-Doppler) allows the detection of small non-palpable nodules, being able to define, in a high percentage of cases, features pointing to the malignant character of a thyroid mass, although the definite assessment of malignancy (invasion of adjacent structures, metastatic cervical nodes) is quite rare. From a diagnostic viewpoint US is required to identify nodules with suspect features, to be submitted to fine needle aspiration biopsy. Moreover, US plays a basic role in the staging--at the cervical level--of carcinomas as well as in the post-operative follow-up. The other imaging modalities (Computed Tomography, Magnetic Resonance Imaging) play a limited role in both staging and post-operative follow-up.

Follow-Up Studies↗